package year2020.month03456;

import java.util.ArrayList;
import java.util.List;

public class MainTest {

    public static void main(String[] args){
        List<String> strList = new ArrayList<>();
        List strTemp = null;
        strList.add("123");
        strList.addAll(strTemp);
        System.out.println(strList);
    }

}
